Conserving Call Logic During Handoff

ABSTRACT

Conserving call logic during handoff may be provided. First, a call may be received at a first server. Next, the first server may determine that it cannot handle the call. Then the call may be transferred by the first server to a second server with enough information so that the second server can take up the call where the first server left off. Transferring the call to the second server with enough information so that the second server can take the call up where the first server left off may comprise placing the information in a REFERRED-BY header and sending the REFERRED-BY header to the second server.

RELATED APPLICATION

This application is a continuation of co-pending U.S. application Ser.No. 12/469,876 entitled “Conserving Call Logic During Handoff” filed May21, 2009, which issued on Oct. 1, 2013 as U.S. Pat. No. 8,547,931, whichis incorporated herein by reference.

BACKGROUND

In a multi-server environment, a call may reach a receiving server. Thereceiving server, however, may determine that it cannot handle the calland may transfer the call to a transfer server so that the call can beserviced. In conventional systems, however, the call is not transferredwith enough context and information so that the transfer serverreceiving the transferred call can seamlessly pick up from where thereceiving server left off.

SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter. Nor is this Summaryintended to be used to limit the claimed subject matter's scope.

Conserving call logic during handoff may be provided. First, a call maybe received at a first server. Next, it may be determined that the callcannot be handled by the first server. Then the call may be transferredto a second server with enough information so that the second server cantake up the call where the first server left off.

Both the foregoing general description and the following detaileddescription provide examples and are explanatory only. Accordingly, theforegoing general description and the following detailed descriptionshould not be considered to be restrictive. Further, features orvariations may be provided in addition to those set forth herein. Forexample, embodiments may be directed to various feature combinations andsub-combinations described in the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this disclosure, illustrate various embodiments of the presentinvention. In the drawings:

FIG. 1 is a block diagram of an operating environment;

FIG. 2 is a flow chart of a method for conserving call logic duringhandoff;

FIG. 3 is a diagram illustrating conserving call logic during handofffor a fax; and

FIG. 4 is a block diagram of a system including a computing device.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings.Wherever possible, the same reference numbers are used in the drawingsand the following description to refer to the same or similar elements.While embodiments of the invention may be described, modifications,adaptations, and other implementations are possible. For example,substitutions, additions, or modifications may be made to the elementsillustrated in the drawings, and the methods described herein may bemodified by substituting, reordering, or adding stages to the disclosedmethods. Accordingly, the following detailed description does not limitthe invention. Instead, the proper scope of the invention is defined bythe appended claims.

Conserving call logic during handoff may be provided. Consistent withembodiments of the invention, in a multi-server environment, a call mayreach a first server. The first server may determine that it cannothandle the call, but it may know that a second server can handle thecall. Consequently, the first server may transfer the call to the secondserver so that the call may be serviced by the second server. Consistentwith embodiments of the invention, the call may be transferred withenough context and information so that the second server may seamlesslypick up the call from where the first server left off. This may beimportant for user experience because, if enough context and informationis not sent along with the call, the user making the call may hear asecond ringing tone and may be forced to re-enter data already enteredinto the first server. In other words, the user may have to start overfrom the beginning of a menu even though the user has already progressedin the menu and may be somewhere deep inside a state machine.Embodiments of the invention may achieve a seamless handoff using asession initiation protocol (SIP) environment using SIP aware devices.

Embodiments of the invention may use a SIP protocol method to transferenough context in mid-call to enable the second server to beginprocessing the call from where the first server left off. Consistentwith embodiments of the invention, the REFER mechanism along with aREFERRED-BY Header may be used to pass adequate call context logic in acall transfer.

FIG. 1 is a block diagram of an operating environment 100 consistentwith embodiments of the present invention. Operating environment 100 maycomprise a calling console 105 (e.g. a telephone), a gateway 110, afirst server 115, a network 120, and a second server 125. Callingconsole 105 may comprise a session initiation protocol (SIP) enabledtelephone. SIP is a signaling protocol widely used for setting up andtearing down multimedia communication sessions such as voice and videocalls over the Internet for example. Gateway 110 may comprise a Voiceover Internet Protocol (VoIP) gateway. VoIP is a general term for afamily of transmission technologies for delivery of voice communicationsover IP networks such as the Internet or other packet-switched networks.Either or both of first server 115 and second server 125 may beimplemented using a computing device 400 as described in more detailbelow with respect to FIG. 4. Network 120 may comprise, but is notlimited to, the Internet, any packet-switched network, or any other typenetwork.

FIG. 2 is a flow chart setting forth the general stages involved in amethod 200 consistent with an embodiment of the invention for conservingcall logic during a call handoff. Method 200 may be implemented using,for example, first server 115 and second server 125. Ways to implementthe stages of method 200 will be described in greater detail below.

Method 200 may begin at starting block 205 and proceed to stage 210where first server 115 may receive a call. For example, a user may makethe call using calling console 105. The call may comprise a Voice overInternet Protocol (VoIP) call. The call may come into gateway 110, whichmay be setup so that all new calls are sent from gateway 110 to firstserver 115.

From stage 210, where first server 115 receives the call, method 200 mayadvance to stage 220 where first server 115 may determine that the callcannot be handled by first server 115. For example, when the call comesin, first server 115 services may ask the user to enter an extension ofa called party. First server 115 may then look up (e.g. query) theentered called party extension in a database. The database may belocated on first server 115 or located on network 120. At this pointfirst server 115 may determine, for example, that the entered calledparty extension is not one serviced by first server 115. For example,first server 115 may determine that a voice mail box associated with theentered called party extension is not located on first server 115.Information obtained by the aforementioned database query may indicate,for example, that the voice mail box associated with the entered calledparty extension is not located on the first server 115, but rather onsecond server 125. In other words, first server 115 may determine thatthe call may be handled by second server 125. For example, the voicemail box associated with the called party associated with the call maybe located on second server 125.

Once first server 115 determines that the call cannot be handled byfirst server 115 in stage 220, method 200 may continue to stage 230where first server 115 may transfer the call to second server 125 withenough information so that second server 125 can take up where firstserver 115 left off. For example, first server 115 may transfer the callto second server 125 through gateway 110. First server 115 may send aREFER to gateway 110 asking gateway 110 to call second server 125. Inthis process, first server 115 may add a REFERRED-BY header includingthe entered called party extension. The following is an example of howsuch a message in SIP might look: REFER-TO:<sip:66242@10.197.92.86;transport=tcp;user=phone> REFERRED-BY:<sip:66250@10.197.118.188>. In addition, first server 115 may also pass,in the REFERRED-BY header, an optional context token to pass secondserver 125 some extra information if needed. Gateway 110 upon receivingthe REFER may copy the REFERRED-BY header and the context token into anew INVITE for gateway 110 to send out to second server 125.

After first server 115 transfers the call in stage 230, method 200 mayproceed to stage 240 where second server 125 may receive the transferredcall. For example, second server 125 may receive the call from gateway110 and second server 125 services may now service the receivedtransferred call. Accordingly, the call may be transferred to secondserver 125 with enough context and information so that second server 125may seamlessly pick up the call from where first server 115 left off byusing data from the REFERRED-BY header. The REFERRED-BY header, forexample, may include the telephone extension number of the userextension associated with the called party associated with the call.Second server 125, upon getting the aforementioned INVITE, may look forthe token in the REFERRED-BY header. If this REFERRED-BY header ispresent, then second server 125 may consume the REFERRED-BY header totransition to the appropriate point in the Finite State Machine anddirectly take the transferred user to the pin-enter prompt.Consequently, the user may be switched to second server 125 from thesame point at which the user left first server 115. Accordingly, secondserver 125 may seamlessly pick up the call from where first server 115left off. In other words, this process may hand off the call to adifferent location and yet may preserve the context of the call so thatthe call can be logically carried on from that point. Once second server125 receives the transferred call in stage 240, method 200 may then endat stage 250.

An embodiment consistent with the invention may comprise a system forconserving call logic during a call handoff. The system may comprise amemory storage and a processing unit coupled to the memory storage. Theprocessing unit may be operative to receive a call at a first server,determine that the call cannot be handled by the first server, andtransfer the call to a second server with enough information so that thesecond server can take up the call where the first server left off.

Another embodiment consistent with the invention may comprise a systemfor conserving call logic during a call handoff. The system may comprisea memory storage and a processing unit coupled to the memory storage.The processing unit may be operative to determine that a call cannot behandled by a first server. In response to the processing unitdetermining that the call cannot be handled by the first server, theprocessing unit may determine that the call can be handled by a secondserver. The processing unit may be operative to transfer the call to thesecond server with enough information so that the second server can takeup the call where the first server left off. The processing unit beingoperative to transfer the call may comprise the processing unit beingoperative to place the enough information in a REFERRED-BY header sendthe REFERRED-BY header to the second server.

Yet another embodiment consistent with the invention may comprise asystem for conserving call logic during a call handoff. The system maycomprise a first server and a second server. The first server maycomprise a first memory storage and a first processing unit coupled tothe first memory storage. The first processing unit may be operative toreceive, from a Voice over Internet Protocol (VoIP) gateway, a callcomprising a Voice over Internet Protocol (VoIP) call and determine thatthe call cannot be handled by the first server. The first processingunit may be further operative to determine that the call can be handledby a second server and to transfer, through the VoIP gateway, the callto the second server with enough information so that the second servercan take up the call where the first server left off. The firstprocessing unit being operative to transfer the call to the secondserver with enough information so that the second server can take thecall up where the first server left off comprises the first processingunit being operative to place the enough information in a REFERRED-BYheader and send the REFERRED-BY header to the second server. The secondserver may comprise a second memory storage and a second processing unitcoupled to the second memory storage. The second processing unit may beoperative to receive the transferred call from the first server.

FIG. 3 is a diagram 300 illustrating conserving call logic duringhandoff for a fax. Consistent with embodiments of the invention, a usermay have a single phone number that may also provide voicemail and fax.Once a messaging server receives the call and the call transitions tofax mode, the messaging server may need to handoff this call to a faxserver for the fax server to process the call and take delivery of thefax. Later the fax server may send the recipient the fax it received bydelivering it to the user's e-mail inbox for example. Similar to theprocess described above with respect to FIG. 2, a call may be handed offto the fax server so that the fax server can continue taking the fax.FIG. 3 illustrates the call sequence diagram for the fax exampledescribed above. In the FIG. 3 process, the REFER is sent along with aREFERRED-BY header, for example: Referred-By:

-   -   sip:exum1.exdc.contoso.com;        msExchUMFaxRecipient=smtp:jdoe@contoso.com;        msExchUMCallingNumber=3457859756. This extra information passed        in the REFERRED-BY header may give enough context to the fax        server to properly compose a fax message for the intended        recipient and later deliver it back to the messaging server.        Consequently, embodiments of the invention may pass enough        context to build the message appropriately and may pass enough        context so that the fax server can continue where the call left        off. Consistent with embodiments of the invention, the caller        may be unaware that the caller has been talking to some other        server (e.g. the fax server.)

FIG. 4 is a block diagram of a system including computing device 400.Consistent with an embodiment of the invention, the aforementionedmemory storage and processing unit may be implemented in a computingdevice, such as computing device 400 of FIG. 4. Any suitable combinationof hardware, software, or firmware may be used to implement the memorystorage and processing unit. For example, the memory storage andprocessing unit may be implemented with computing device 400 or any ofother computing devices 418, in combination with computing device 400.The aforementioned system, device, and processors are examples and othersystems, devices, and processors may comprise the aforementioned memorystorage and processing unit, consistent with embodiments of theinvention.

With reference to FIG. 4, a system consistent with an embodiment of theinvention may include a computing device, such as computing device 400.In a basic configuration, computing device 400 may include at least oneprocessing unit 402 and a system memory 404. Depending on theconfiguration and type of computing device, system memory 404 maycomprise, but is not limited to, volatile (e.g. random access memory(RAM)), non-volatile (e.g. read-only memory (ROM)), flash memory, or anycombination. System memory 404 may include operating system 405, one ormore programming modules 406, and may include a program data 407.Operating system 405, for example, may be suitable for controllingcomputing device 400′s operation. In one embodiment, programming modules406 may include, for example, a handoff application 420. Furthermore,embodiments of the invention may be practiced in conjunction with agraphics library, other operating systems, or any other applicationprogram and is not limited to any particular application or system. Thisbasic configuration is illustrated in FIG. 4 by those components withina dashed line 408.

Computing device 400 may have additional features or functionality. Forexample, computing device 400 may also include additional data storagedevices (removable and/or non-removable) such as, for example, magneticdisks, optical disks, or tape. Such additional storage is illustrated inFIG. 4 by a removable storage 409 and a non-removable storage 410.Computer storage media may include volatile and nonvolatile, removableand non-removable media implemented in any method or technology forstorage of information, such as computer readable instructions, datastructures, program modules, or other data. System memory 404, removablestorage 409, and non-removable storage 410 are all computer storagemedia examples (i.e., memory storage). Computer storage media mayinclude, but is not limited to, RAM, ROM, electrically erasableread-only memory (EEPROM), flash memory or other memory technology,CD-ROM, digital versatile disks (DVD) or other optical storage, magneticcassettes, magnetic tape, magnetic disk storage or other magneticstorage devices, or any other medium which can be used to storeinformation and which can be accessed by computing device 400. Any suchcomputer storage media may be part of device 400. Computing device 400may also have input device(s) 412 such as a keyboard, a mouse, a pen, asound input device, a touch input device, etc. Output device(s) 414 suchas a display, speakers, a printer, etc. may also be included. Theaforementioned devices are examples and others may be used.

Computing device 400 may also contain a communication connection 416that may allow device 400 to communicate with other computing devices418, such as over a network in a distributed computing environment, forexample, an intranet or the Internet. Communication connection 416 isone example of communication media. Communication media may typically beembodied by computer readable instructions, data structures, programmodules, or other data in a modulated data signal, such as a carrierwave or other transport mechanism, and includes any information deliverymedia. The term “modulated data signal” may describe a signal that hasone or more characteristics set or changed in such a manner as to encodeinformation in the signal. By way of example, and not limitation,communication media may include wired media such as a wired network ordirect-wired connection, and wireless media such as acoustic, radiofrequency (RF), infrared, and other wireless media. The term computerreadable media as used herein may include both storage media andcommunication media.

As stated above, a number of program modules and data files may bestored in system memory 404, including operating system 405. Whileexecuting on processing unit 402, programming modules 406 (e.g. handoffapplication 420) may perform processes including, for example, one ormore method 200's stages as described above. Handoff application 420 maybe executed on either one of or both of first server 115 and secondserver 125. The aforementioned process is an example, and processingunit 402 may perform other processes. Other programming modules that maybe used in accordance with embodiments of the present invention mayinclude electronic mail and contacts applications, word processingapplications, spreadsheet applications, database applications, slidepresentation applications, drawing or computer-aided applicationprograms, etc.

Generally, consistent with embodiments of the invention, program modulesmay include routines, programs, components, data structures, and othertypes of structures that may perform particular tasks or that mayimplement particular abstract data types. Moreover, embodiments of theinvention may be practiced with other computer system configurations,including hand-held devices, multiprocessor systems,microprocessor-based or programmable consumer electronics,minicomputers, mainframe computers, and the like. Embodiments of theinvention may also be practiced in distributed computing environmentswhere tasks are performed by remote processing devices that are linkedthrough a communications network. In a distributed computingenvironment, program modules may be located in both local and remotememory storage devices.

Furthermore, embodiments of the invention may be practiced in anelectrical circuit comprising discrete electronic elements, packaged orintegrated electronic chips containing logic gates, a circuit utilizinga microprocessor, or on a single chip containing electronic elements ormicroprocessors. Embodiments of the invention may also be practicedusing other technologies capable of performing logical operations suchas, for example, AND, OR, and NOT, including but not limited tomechanical, optical, fluidic, and quantum technologies. In addition,embodiments of the invention may be practiced within a general purposecomputer or in any other circuits or systems.

Embodiments of the invention, for example, may be implemented as acomputer process (method), a computing system, or as an article ofmanufacture, such as a computer program product or computer readablemedia. The computer program product may be a computer storage mediareadable by a computer system and encoding a computer program ofinstructions for executing a computer process. The computer programproduct may also be a propagated signal on a carrier readable by acomputing system and encoding a computer program of instructions forexecuting a computer process. Accordingly, the present invention may beembodied in hardware and/or in software (including firmware, residentsoftware, micro-code, etc.). In other words, embodiments of the presentinvention may take the form of a computer program product on acomputer-usable or computer-readable storage medium havingcomputer-usable or computer-readable program code embodied in the mediumfor use by or in connection with an instruction execution system. Acomputer-usable or computer-readable medium may be any medium that cancontain, store, communicate, propagate, or transport the program for useby or in connection with the instruction execution system, apparatus, ordevice.

The computer-usable or computer-readable medium may be, for example butnot limited to, an electronic, magnetic, optical, electromagnetic,infrared, or semiconductor system, apparatus, device, or propagationmedium. More specific computer-readable medium examples (anon-exhaustive list), the computer-readable medium may include thefollowing: an electrical connection having one or more wires, a portablecomputer diskette, a random access memory (RAM), a read-only memory(ROM), an erasable programmable read-only memory (EPROM or Flashmemory), an optical fiber, and a portable compact disc read-only memory(CD-ROM). Note that the computer-usable or computer-readable mediumcould even be paper or another suitable medium upon which the program isprinted, as the program can be electronically captured, via, forinstance, optical scanning of the paper or other medium, then compiled,interpreted, or otherwise processed in a suitable manner, if necessary,and then stored in a computer memory.

Embodiments of the present invention, for example, are described abovewith reference to block diagrams and/or operational illustrations ofmethods, systems, and computer program products according to embodimentsof the invention. The functions/acts noted in the blocks may occur outof the order as shown in any flowchart. For example, two blocks shown insuccession may in fact be executed substantially concurrently or theblocks may sometimes be executed in the reverse order, depending uponthe functionality/acts involved.

While certain embodiments of the invention have been described, otherembodiments may exist. Furthermore, although embodiments of the presentinvention have been described as being associated with data stored inmemory and other storage mediums, data can also be stored on or readfrom other types of computer-readable media, such as secondary storagedevices, like hard disks, floppy disks, or a CD-ROM, a carrier wave fromthe Internet, or other forms of RAM or ROM. Further, the disclosedmethods' stages may be modified in any manner, including by reorderingstages and/or inserting or deleting stages, without departing from theinvention.

All rights including copyrights in the code included herein are vestedin and the property of the Applicant. The Applicant retains and reservesall rights in the code included herein, and grants permission toreproduce the material only in connection with reproduction of thegranted patent and for no other purpose.

While the specification includes examples, the invention's scope isindicated by the following claims. Furthermore, while the specificationhas been described in language specific to structural features and/ormethodological acts, the claims are not limited to the features or actsdescribed above. Rather, the specific features and acts described aboveare disclosed as example for embodiments of the invention.

What is claimed is:
 1. A method for conserving call logic duringhandoff, the method comprising: receiving a call at a first server;determining that a voice mail box associated with a called partyassociated with the call is not located on the first server; querying adatabase on a network to determine where the voice mail box associatedwith the called party is located; determining that the voice mail boxassociated with the called party associated with the call is located onthe second server; and transferring the call to the second server. 2.The method of claim 1, wherein transferring the call to the secondserver comprises enabling the second server to transition to a pointwithin a state machine where the first server left off, the point withinthe state machine representing a location and a context of the callwhere the first server left off.
 3. The method of claim 1, whereinreceiving the call at the first server comprises receiving the callcomprising a Voice over Internet Protocol (VoIP) call.
 4. The method ofclaim 1, wherein receiving the call at the first server comprisesreceiving the call from a Voice over Internet Protocol (VoIP) gateway.5. The method of claim 4, wherein receiving the call from the Voice overInternet Protocol (VoIP) gateway comprises receiving the call at theVoice over Internet Protocol (VoIP) gateway from a calling consolecomprising a session initiation protocol (SIP) enabled telephone.
 6. Themethod of claim 1, wherein determining that the call cannot be handledby the first server comprises determining, by the first server, that thecall cannot be handled by the first server.
 7. The method of claim 1,wherein determining that the call cannot be handled by the first servercomprises determining, by the first server, that a voice mail boxassociated with a called party associated with the call is not locatedon the first server.
 8. The method of claim 1, wherein transferring thecall to the second server comprises transferring the call through aVoice over Internet Protocol (VoIP) gateway to the second server.
 9. Themethod of claim 1, wherein transferring the call to the second serverwith enough information so that the second server can take the call upwhere the first server left off comprises: placing the enoughinformation in a REFERRED-BY header; and sending the REFERRED-BY headerto the second server.
 10. The method of claim 9, wherein placing theenough information in the REFERRED-BY header comprises placing theenough information in the REFERRED-BY header wherein the enoughinformation comprises a telephone extension number of a user extensionassociated with a called party associated with the call.
 11. The methodof claim 1, further comprising receiving the transferred call at thesecond server.
 12. The method of claim 1, further comprising, inresponse to determining that the call cannot be handled by the firstserver, determining by the first server that the call can be handled bythe second server.
 13. A computer-readable medium that stores a set ofinstructions which when executed perform a method for conserving calllogic during handoff, the method executed by the set of instructionscomprising: determining that a call cannot be handled by a first server;determining that a voice mail box associated with a called partyassociated with the call is not located on the first server; querying adatabase on a network to determine where the voice mail box associatedwith the called party is located; determining that the voice mail boxassociated with the called party associated with the call is located onthe second server; and transferring the call to the second server. 14.The computer-readable medium of claim 13, wherein transferring the callto the second server with enough information so that the second servercan take the call up where the first server left off comprises: placingthe enough information in a REFERRED-BY header; and sending theREFERRED-BY header to the second server.
 15. The computer-readablemedium of claim 14, the REFERRED-BY header being configured to enablethe second server to transition to a point within a state machine wherethe first server left off, the point within the state machinerepresenting a location and a context of the call where the first serverleft off.
 16. The computer-readable medium of claim 14, wherein placingthe enough information in the REFERRED-BY header comprises placing theenough information in the REFERRED-BY header wherein the enoughinformation comprises a telephone extension number of a user extensionassociated with a called party associated with the call.
 17. Thecomputer-readable medium of claim 13, further comprising receiving thecall at the first server.
 18. The computer-readable medium of claim 17,wherein receiving the call at the first server comprises receiving thecall comprising a Voice over Internet Protocol (VoIP) call.
 19. A systemfor conserving call logic during handoff, the system comprising: amemory storage; and a processing unit coupled to the memory storage,wherein the processing unit is operative to: receive, from a Voice overInternet Protocol (VoIP) gateway, a call comprising a Voice overInternet Protocol (VoIP) call, determine that a voice mail boxassociated with a called party associated with the call is not locatedon the first server, query a database on a network to determine wherethe voice mail box associated with the called party is located,determine that the voice mail box associated with the called partyassociated with the call is located on the second server, and transfer,through the VoIP gateway, the call to the second server.
 20. The systemof claim 19, wherein the second server is enabled to transition to apoint within a state machine where the first server left off, the pointwithin the state machine representing a location and a context of thecall where the first server left off.